September 28, 2010
The Other Threat to The Gulf of Mexico
Animal agriculture and the dead zone
by Elissa Lane
BP may have stifled its rogue oil well, but before you breathe a sigh of relief for marine life, consider that Gulf waters are regularly polluted without media fanfare. One of the principal culprits is not an oil company, but animal agriculture.
Pollution from industrial animal agriculture is a leading contributor to the Gulf dead zone, which occurs when water oxygen levels drop too low for some water-dwelling animals to survive.
The resulting dead zone in the Gulf is one of the largest in the world, and it will continue to cause environmental devastation unless we change our agricultural practices and dietary habits.
This year's Gulf dead zone, with an area roughly the size of New Jersey, is reportedly one of the largest since researchers started mapping in 1985. While the dead zone used to strike the Gulf every few years, it now forms every spring, killing aquatic life, destroying habitat, and altering the marine food web. Low oxygen levels, or "hypoxia," can inhibit growth of marine organisms and in extreme cases can lead to fish kills. For example, hypoxia in North Carolina's Neuse River Estuary killed millions of fish in 1995, and was linked to two more kills in the following years, affecting tens of thousands of fish.
Farm Animal Waste and Fertilizer
Fertilizer used to grow animal feed is perhaps the most significant offender, as the vast majority of U.S. feed and industrial farm animal production is concentrated in the Mississippi drainage basin. Animal agriculture uses more than 70 percent of Mississippi basin grain production, and 169 million tons of grain per year goes into feed troughs. Experts blame nitrogen fertilizer used on these crops for exacerbating the flow of pollutants into the Mississippi River and then into the Gulf of Mexico.
According to a report by the Food and Agriculture Organization of the United Nations, not only may animal agriculture "bear the prime responsibility for worsening hypoxia in the northern Gulf of Mexico," but it is likely "the leading contributor to water pollution by nitrogen in the United States."
Farm animal waste also contributes an estimated 15 percent of nitrogen influx into the Gulf of Mexico. Meat and dairy production in the United States has largely shifted from small farms to outsized "concentrated animal feeding operations" which may hold hundreds of thousands of animals. According to the U.S. Department of Agriculture, "the major source of environmental degradation from confined animal production is the wastes (manure, urine, bedding material) that are produced." Nitrogen from farm animal waste may end up in waterways through deposits into freshwater sources, farm building runoff, leaks from storage facilities, and over-application.
A Shift in Diet Can Help Restore the Gulf
Individual food choices could be decisive in restoring the Gulf of Mexico. According to the FAO report, "a dietary shift away from grain-fed beef to vegetarianism in the United States could reduce total land and fertilizer demands of Mississippi Basin crops by over 50 percent, with no change in total production of human food protein." This shift would minimize or eliminate the Gulf dead zone by reducing the Mississippi River's flow of nitrogen into the Gulf.
To learn more about the effects of animal agriculture on the environment, please read An HSUS Report: The Impact of Industrialized Animal Agriculture on the Environment [PDF].
Elissa Lane is an assistant campaign manager at Humane Society International Farm Animals.